Automatic slack-adjuster for brakes.



n n. 711,750. Patented out. 2|, |902.

E. wlLsoN. AUTUMATIG SLACK ADJUSTER FOR BRAKES.

(Applipmion medV Apr. 14, 1902.)

3 Sheets-Sheet I..

(No Rodel.)

- Patented` Oct. 2|, |902. |a. wu.s0N. AUTOMATIC SLACK ADJUST-ER FRBRAKES.

(Application med Apr. 14, 1902.) l

' 3 Sheets-Sheet 2.

No. 7||,75o. Patented ont., 2|, |902.

E. wlLsnN.

AUTOMATIC SLACK ADJUSTER F08 BRAKES.

(Application led Apr. 14, 1902.) (No Model.) 3 Sheets-Sheet 3.

UNITED `STATES PATENT OFFICE.

EDVARD WILSON, OF ST. LOUISrMISSOURI.l

AUTO MATIC S LACK-ADJ USTER FO R BRAKES.

SPECIFICATION forming part of Letters Patent No. 711,750, 4dated October21, 1902. Application filed April 14, IQO. Serial No. 102.783- (Nomodel.)

To all whom, it 11m/y con/cern,.-

Be it known that I, EDWARD WILSON, a citizen of the United States,residing in the city of'St. Louis, State of Missouri, have inventedcertain new and vuseful Improvements in Automatic Slack-Adjusters forBrakes; and I hereby declareA the following to be a full, clear, andexact description of the same, reference being had to the accompanyingdrawings, in which-.-

Figure l is a plan View or diagram illustrating a slack-adjuster forcar-brakes which embodies my invention as applied to airbrakes forpassenger service. In this view the cylinder-levers are shown as the oneconnected with the air-brake-piston rod and the other supported from thecylinder-head, the arrangement of said levers being the same asvcommonly followed,exoepting that the adjuster motor mechanismissupported from the air-brake-cylinder head and interposed between theair-brake cylinder and the cylinder-lever. Fig. 2 is ,a detachedenlarged view, partly in section, of the slack-adjuster motor, theadjuster mechanism actuated thereby, the fulcrum-block of the levercontrolled by the adjuster mechanism, the guideframe of thefulcrum-block, and parts of the levers. In this view both the levers aresupported on the guide-frame of the adjuster mechanism, which is thepreferred arrangement when the adjuster motor and mechananism are totake up slack onthe equalizingrod of the cylinder-levers or the motor isnot supported from the air-brake cylinder. Fig. 3 is a transversesection on the line 3 3, Fig. 2, showing one form of clutch mechanismforming an element of the adjuster mechanism. Fig. I is a sideelevation, partly in section, of the motor-cylinder, together with alongitudinal central section of the valvechamber and valve. Fig. 5 is alongitudinal section of the motorcylinder,showing a modied form ofclutch mechanism-viz., the pawl and ratchet in lieu of the ball-clutchof Fig. l. FigQG is a transverse section lon the line 6 6, Fig. 5,showing themodied clutch or pawl-and-ratchet mechanism substituted forthe ball-clutch of Fig. l.

Like symbols refer to like parts wherever they occur.

My invention relates to that class ofl devices, commonly termedslack-adjusters, employed to take up or eliminate the slack fromcar-brake systems, said slack arising from wear in general andespecially from brake-shoe wear.

All those familiar with air-brake practice are aware that in order toobtain uniform braking pressures the pressure in the auxiliary reservoirmust be constant and the travel of the piston of the brake-cylindermaintained within certain limits, and on this theory the adjustment ofthe brake system is arranged for a given travel of the brake-cyll inderpiston. The wear of the brake-shoes and other portions of the brakesystem, or foundation-brakes, as they are sometimes termed, results inrgradually increasing slack or lost motion, which, if not eliminated fromthe system, in time results in gradual loss or reduction of the brakingpower and mayiinally end in the bottoming of the air-brake piston beforethe slack or lost motion is taken up, and the brakes be thus renderedinoperative. In order to maintain uniform braking pressure and aconstant piston-stroke, which can only be accomplished by an automaticelim-ination ofthe slack incident to brake wear, two general methodshave been heretofore adopted-viz, the automatic adjustment ofthe fulcraof the'levers and the shortening of the pull-rods, connecting-rods, orequalizing-rods of the brake system, the mechanism employed beingcomprised in whole or in part of screw and pawl-and-ratchet elements,actuated either mediately or immediately by the excess of travel theair-brake piston. In some instances the excess travel of the piston hasbeen utilized through the medium of positive elements, such as tappetsor cams, and in other instances by the motive liuid of the brakes and anindependent motor actuated by the motive-fluid pressure.

My present invention `therefore relates, more specifically stated, tothat class of slackadjusters wherein the excessof piston travell isutilized through themediu'm of an independent adj uster-motor energizedby the motive fluid of the brake systemand controlled by the pistontravel, the slack elimination being accomplished by preference throughshifting of the lever fulcra of the brake system or taking up slack onthe equalizing-rods.

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v invention.

In carrying out my invention and in order to obtain Yfrom time to timean automatic movement of the lever fulcrum oradj ustment of thepull-rods or equalizing-rod, as the case may be, I combine with meansfor actuating the same a plurality of rotatable concentric sleeves, oneof which actuates the other, and a clutch or ratchet mechanism actuatedby one of said sleeves, and such a combination embodies one feature ofmy invention. I further combine with said rotatable concentric sleevesand clutch mechanism and means for actuating the same a threaded rod andnut mechanism for converting the rotary into a rectilinear movement foreliminating the slack from a brake system, and such a combinationembodies a second feature of my I further combine with said rotatableconcentric sleeves and clutch mechanism a cylinder and its piston, avalve mechanism,and such suitable connections with the train-pipe orlike source of motive-fluid pressure as will automatically actuate theslackadjuster mechanism from or-by the motiveluid pressure of thesystem, and I control the said operation by the excess travel of thebrake-piston, and such a combination emy 6 of a ball-clutch mechanism.The head l There are other minor features of inven-l bodies a thirdfeature of my invention.

tion, all as will hereinafter more fully appear.

I willl nowV proceed to describe my invention more fully, so that othersskilled in the art to whichit appertains may apply the same.'

In Figure l of the drawings, which illustrates the arrangement of anair-brake system for passenger service, A indicates the auxiliaryreservoir; B, the train-pipe; C, the airbrake cylinder; T, the triplevalve, said parts having the usual connections with each other, and a bthe cylinder-levers, one of which, a, is connected with the piston-rodof the brakecylinder C,while the other, b, is provided with afulcrum-block 9, movable on the ways 10a, constituting a guide-bracketsecured to the head of air-brake cylinder C or otherwise properlysupportedl in relation thereto and to the levers of the brake system.Said levers a b are connected with each other by the usualequalizing-rod F and with the lever system of the foundation-brakes bythe usualpull-rods p p. E (on the diagram Fig. l) represents thelocation and relative connection of my adjuster-motor and slack-take-upmechanism-that is to say, on the guide-bracket 10a of the movablefulcrum-block of lever 1?- and connected with the train-pipe B by thepipe e and with the air-brake cylinder by the pipe f, the connection ofpipefwith the airbrake cylinder being at such a point that communicationbetween the air-brake cylinder and the motor-cylinder E shall beestablished only when the piston of the air-brake cylinder exceeds itsnormal travel in applying the brakes.

Referring to Figs. 2 and 4 of the drawings,

it will be seen that my adjuster devices comprise a motor-cylinder E,connected with the train-pipe B or other suitable source ofInotive-tluid pressure through the intermediate valve-chamber l, Fig. 4,and with the movable fulcrum-block 9 of lever b by an intermediatepiston and a screw-rod l1 or threaded rod. The motor of theslack-adjuster mechanism consists of the cylinder E, its annular piston2, the sleeve extension 3 of the piston provided with the annularthreaded end section 4, having on its interior spirally-arranged orrifle grooves, which receive the spirallyarranged ribs on the exteriorof the central or included sleeve 5. Between the piston-sleeve 3 and thecentral rotatable sleeve 5 is the piston return-spring S, which servesto return the piston to its normal position when the fluid-pressure iswithdrawn, and between the piston 2, sleeve 3, and the end section 4 aresecured suitable piston-packings 2" and 3a. The central or includedsleeve 5 is threaded on its interior at or near its outer end, asindicated by dotted lines, (see 5h,) to constitute a feed-nut foroperation with the threaded rod 11, and on its eX- terior, adjacentthereto, is provided with the notched flange 5d or ball-races for theballs of the motor cylinder l is recessed, as at 1", to form a chamberfor the reception of the notched flange or ball-race 5d on the end ofthe central sleeve 5 and also to receive the balls 6 of the ball-clutchmechanism. The chamber lb is separated from the piston-chamber of thecylinder by an annular plate or partition 6a, which together with thepistonhead la form journals or bearings for the central rotatable rifledsleeve 5. On the projecting end of the rotatable central sleeve 5 is ahand-wheel 7, whereby the said sleeve may be reversely rotated when itis desired to manually adjust the devices for renewal of brake-shoes,&c., and in order that the clutch mechanism may be freed for suchpurpose the clutch-chamber 1b is formed with a loose or rotatable cuplining or bushing 8, which may be iixed or released by manipulating aset-screw see Fig. 3, dotted lines) 8a passing through the cylinder-head1tL or by other suitable means. 9 indicates the fulcrum-block for thelever b, said block being movable in a guide frame or bracket composedof the end. casting 10 and the side bars or fulcrum-block ways 10a, thelatter connected with the head 1a of the motor-cylinder E by theirthreaded ends and nuts or in other suitable manner. Where themotor-cylinder and` adjuster mechanism are to be supported from theair-brake cylinder, as in Fig. l, the casting 10 may be dispensedwithybut where the motor-cylinderE is to be supported independently ofthe air-brake cylinderA C it may be used to complete the guide-frame ofthe fulcrum-block 9, as in Fig. v2, and in such instance may also aordsupport to the other lever a, and such will be the preferredconstruction Where the slack-adjuster mechan- IOO IIO

ism is to be applied to the equalizing-rod F of the cylinder-levers orto other equalizing or pull rods of the brake system. The lever b, whichis pivoted on the fulcrum-block 9, is preferably a forked lever or onewhich is bifurcated to straddle the guide-bar 10a (or frame-bar) tocounteract vibration from side thrust when the brakes are applied.Formed with or mounted on the motor-cylinder E or otherwise properlylocated with relation thereto is a valve-chamber 1, having the port 132Lleading to the train-pipe B or other suitable source of motive-fluidpressure, the port 13C leading to the air-brake cylinder C and the ports13b, 13d, and 13e leading to the motorcylinder E. 14 indicates apiston-valve within the valve-chamber 1, so formed that the ports 1313", leading from the train-pipe to the motor, open between the heads ofthe piston, while the port 13C, leading from the airbrake cylinder,opens on one head ofthe piston, and the ports 13d and 13e, connectingthe motor-cylinder E and valve-chamber as also the exhaust-port 13f,open on the other or opposite head of the piston. By this arrangement ofthe ports, dac., of the valve-chamber 1 it will be noted that the valve14 is aected by motive-fluid pressure from the brake-cylinder C, whilethe piston 2 of the motor-cylinder Eis operated in one direction by themotive-Huid pressure from the train-pipe B whenever the piston of theair-brake cylinder C exceeds its 'normal travel and opens the portleading through pipe j' to the port 13c of the valve-chamber and thevalve 14 is shifted to open the port 13b, leading from the valve-chamberto the motor-cylinder E, the port 13, which leads from the train-pipe,being always open. The reverse movement of the piston 2 of themotor-cylinder is effected by the expansion of spring S, which has beencompressed by the first-noted movement of piston 2.

In lieu of the ball-clutch mechanism shown in the principal gures (2 and3) of the drawings a pawl-and-ratchet mechanism may be employed torestrain the reverse rotation of the central sleeve 5 and nut 5b, ifdesired, and the application of the same has been shown in Figs. 5 andof the drawings. In this construction the only changes required are thesubstitution of the ratchet-wheel R for the ball-races 5Ll of thecentral sleeve 5 and to attach to the bushing` 8 the pawl P and itsspring s in lieu of the balls 6.

The .construction and arrangement of the devices being substantially ofthe character hereinbefore pointed out, their operation will be asfollows: The connections between the train-pipe B, the air-brakecylinder C, and the motor-cylinder E through the intermediatevalve-chamber 1 being, as hereinbefore noted, and the valve 14 andpiston 2 being in their normal position, as shown in Fig. 4 of thedrawings, the motive-Huid pressure from the train-pipe through port 13will be between the heads of the valve 14,whioh valve will remainbalanced or unaffected by the pressure so long as there is no slack inthe system. When, however, slack arises and the air-brake piston exceedsits normal travel, soas to open the port of pipe f, pressure from theair-brake cylinder Will enter the valvechamber 1 through port 13anddestroying the balance of valve 14 said valve will be forced over (tothe right, Fig. 4) until port 13b,leading to the motor-cylinder, isopened, whereupon piston 2 of the motor will be forced over (to right,Fig. 4) and will compress the returnspring S, slack being taken up onthis movement of the piston. As soon as the motorpiston 2 passes port 13(which does not occur until the brakes are fully released) the pressurewhich has served to move the motorpiston 2 enters the valve-chamberagainst the head of valve 14, and the pressure from port 13c on theopposite head of the valve-piston having been withdrawn the valve 14 isforced back to its normal position, as shown in Fig. 4, the port 13b isclosed, the exhaust-port 13t is opened, and the return-spring S expands,forcing motor-piston 2 back to its normal position, Where it remainsuntil further slack is to be taken up. The piston 2 in its firstmovement (to the right, Figs. 2 and 4) under the motive-fluid pressurewill move in a right line, and at that time the central or includedsleeve 5 being free of the clutch will be rotated to actuate thethreaded rod 11 and take up the slack, as before' noted; but at the timethe reverse movement of the piston 2 (to the left, Figs. 2 and 4) underthe operation of return-spring S occurs the central or included sleeve 5will be held against reverse rotation by the clutch mechanism.Consequently the sleeve 3 and sleeve extension 4, as well as the piston2, will rotate, the piston-packings at that time being loose or freefrom the pressure of the motive iiuid. If it is deemed desirable thatthe piston 2 should not rotate, the sleeve 3 and sleeve extension or endsection 4 may be constructed to rotate independently of the piston 2.When the parts are to be readjusted for removing worn brake-shoes andsupplying new or for like purposes, the set-screw 8a will be manipulatedto release the cup or bushing S and allow the same to revolve with thecentral sleeve 5 and its nut 5", and the parts may then be reverselyturned by means of the hand-wheel 7.

As my invention has been especially devised for use with an air-brakesystem and has been shown by preference in connection with apassenger-service equipment, the adj usting mechanism (rifledsleeves,clutch, nut, and rod) has been Shown in Fig. 1 as applied to themovement of the fulcrum-block of one of the cylinder-levers and themotor has been shown asoperated by vmotive duid from the train-pipe Band controlled by motive-fluid pressure from the air-brake cylinder C. iYet it will be at once evident to persons skilled in the art that theadjusting mechanism-to wit,

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the concentric rotatable ritled sleeves, clutch mechanism, nut, androd-constitutes an operative combination which may be otherwise actuatedand adapted for adjusting the equalizing-rod (see Fig. 2) or shorteningthe pullrods, as well as for shifting the fulcra of the levers of thefoundation-brakes; also,that the motive fluid for operating themotor-piston may be taken as well from any other point of the air-brakesystem as from the train-pipe, and, further, that the valve of the motormay be controlled by the excess travel of any part of thefoundation-brake system o1' directly from the stem of the air-brake pis'ton as Well as by motive fluid from the airbrake cylinder, and all ofsuch adaptations I intend to include Within the scope of my claims,except Where the terms of the claims exclude the same.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

l. In a slack-adjuster mechanism, the combination of a plurality ofconcentric rotatable sleeves one of which actuates the other and a lclutch mechanism actuated by one of said sleeves, substantially as andfor the purposes specified.

2. In a slack-adjuster mechanism, the com-l bination of aplurality ofconcentric rotatable sleeves one of which actuates the other, and a rodand a clutch mechanism actuated by one of said sleeves, substantially asand for the purposes speciiied.

3. In a slack-adjuster mechanism, the combination with a threaded rod,of a plurality of concentric rotatable sleeves one of Which is actuatedby the other, a clutch mechanism and a feed-nut for the rod,substantially as and for the purposes specified.

4. In a slack-adjuster mechanism, the combination with a threaded rod,of a plurality of concentric sleeves one of Which is rilied, a

plurality of concentric rotatable sleeves one of which actuates theother and is actuated by the piston, and a rod actuated by one of saidsleeves, substantially as and for the purposes specified. n

7. In a'slack-adjuste'r mechanism, the combination with a cylinderhaving ports forthe admission of a motive iiuid, of a piston, aplurality of concentric rotatable sleeves one of which is actuated bythe other and one by the piston, a clutch actuated by one of saidsleeves, and a rod actuated by one of said sleeves, substantially as andfor the purposes specified.

8. Ina slack-adj uster mechanism, the combination with a motor-cylinderhavinga port for the admission of a motive fluid, of a valve for saidport, means Jfor controlling the movement of the valve from the brakesystem, a piston within said motor-cylinder, a plurality of concentricsleeves one of which actuates the other and is actuated by the piston,and a rod actuated byone of said sleeves, substantially as and for thepurposes specified.

9. In a slack-adjuster mechanism for an air-brake system, thecombination of a motorcylinder havingy portsand a suitable valvetherefor, connections with the train-pipe and with the air-brakecylinder, a piston for the motor-cylinder, and adjuster mechanismactuated by the piston of the motor-cylinder, substantially as and forthe purposes specified.

lO. In a slack adjuster mechanism, the combination of concentricrotatable sleeves one of which actuates the other, a clutch mechanismfor the actuated slee ve,.means for throwing the clutch out ofengagement, and a rod actuated by the sleeve which is controlled by theclutch, substantially as and for the purpose specied.

11. In a slack adjuster mechanism, the combination with concentricrotatable sleeves 4 and 5, the latter provided with clutch mechanism,vofa rotatable cup lining or bushing for receiving the clutch and means forsecuring said cup lining or bushing against rotation, substantially asand for the purposes specified.

In testimony whereof I affix my signature, in presence of two witnesses,this 10th day of April, 1902.

' EDWARD WILSON. Witnesses:

F. E. SCHWENTLER, C. C. ZIEGLER.

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